[a2800276]

s/universe/solar system/

There are still plenty of other possibile curiosities than interstellar rocks in closer proximity than Proxima Centauri. Each would require highly specialized instruments.

Not sure what the window of opportunity was for O6a, but it's doubtful that it would have been possible to prepare a mission in that timeframe. It follows that such "spaceships" would need to be prepared ahead of time and maintained indefinitely for an event which may not occur again for centuries ...